SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bd3089f250190d68e136051951735ded794591ac4820f5b1ebc0bff18f86116' 
  AND token = 'SYsouZijxL9HlieqovyF/IOTMgJrY6BCuWzkhsFsGco=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}